Pay-per-call API platform on Base (USDC) offering data, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is an x402-enabled API platform that provides a broad catalog of pay-per-request endpoints settled in USDC on the Base network. The specific endpoint at `/api/v1/inbox/142` is listed as "Premium API Access" and costs up to $0.02 per call (20,000 base units of USDC with 6 decimals). Payment is handled via the x402 protocol — no API keys, accounts, or subscriptions are required; callers attach an X-PAYMENT header to each request.
The wider platform advertises four endpoint categories: Data & Analytics (metrics, reports, data export, insights), AI & Machine Learning (sentiment analysis, text summarization, classification, embeddings), Finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and Infrastructure utilities (geocoding, validation, conversion, generation). All listed endpoints share the same $0.02/request pricing with no rate limits or minimum commitments.
Important caveat: the specific functionality behind `/api/v1/inbox/142` is not documented beyond the label "Premium API Access." There is no OpenAPI schema, no request/response examples, and the crawled docs pages (pricing, README, API) returned only a wallet-connect prompt with no additional content. Agents should treat this endpoint as opaque until further documentation is available.
Capabilities
Use cases
- —Programmatic access to a pay-per-call API without needing an account or API key
- —Agent-driven workflows that settle per-request costs in USDC on Base
- —Integrating low-cost utility or data endpoints into automated pipelines
Fit
Best for
- —Developers wanting zero-signup, pay-as-you-go API access
- —AI agents with x402-compatible payment capabilities
- —Users who prefer crypto-native micropayments over subscription billing
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —Applications requiring guaranteed SLAs or enterprise support
- —Users without access to USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/inbox/142 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base), but there is no OpenAPI schema, no request/response examples, and no documentation explaining what /api/v1/inbox/142 actually does. The crawled pages beyond the landing page returned only wallet-connect prompts with no useful content.
Warnings
- —No documentation exists for the specific endpoint /api/v1/inbox/142 — its actual functionality is unknown
- —No OpenAPI or JSON schema is provided for request or response formats
- —Docs, pricing, and README pages all returned only a wallet-connect prompt with no content
- —The endpoint name 'Premium API Access' is generic and does not describe a concrete capability
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/inbox/142
- —All listed endpoints cost $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/inbox/142